Hydraulic pressure from System B will be used to raise the landing gear:
A.A.When System A pressure is low and the landing lever is positioned up
B.B.When the ALTERNATE NOSE WHEEL Switch is positioned ON
C.C.When the No.1 engine RPM drops below a limit value with the landing gear still down and the landing gear is positioned up
D.D.After a failure of the No.1 engine hydraulic pump with the landing gear still down and the landing gear is positioned up
正确答案是C